1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device including a process of forming a bump on a pad of a semiconductor chip.
2. Description of the Related Art
A method of weakening the base portion of a gold wire connected to a bump after the bump is formed is disclosed in Japanese Patent Application Laid-Open No. 5-235002. In this related art, a capillary is horizontally moved after the formation of the bump, and the base portion of the gold wire connected to the bump is weakened. The weakening of the base portion of the gold wire has an advantage of being able to make cutting of the gold wire easy.
However, when the capillary is to be horizontally moved after formation of the bump, and if the moving speed is set to be equal to the moving speed of the capillary in the formation of the bump, then the shape and size of the weakened base portion of the gold wire become disadvantageously unstable due to high moving speed of the capillary. When the base portion still has excessively high strength, although the base portion is weakened, a projection extending upward is formed on the base portion in cutting process, and mechanical impact in the cutting process increases. At the moment the gold wire is cut, the gold wire fed from the capillary is bent and adversely affects a subsequent bonding operation. On the other hand, when the base portion is excessively weakened, the bump and the gold wire are disconnected from each other in the process of weakening. As a result, a gold wire cannot be fed from the capillary by a predetermined length for the next bonding operation.